PPAPI: Add PluginPrivateFileSystem

ppapi/shared_impl/file_system_util.cc

Index: ppapi/shared_impl/file_system_util.cc
diff --git a/ppapi/shared_impl/file_system_util.cc b/ppapi/shared_impl/file_system_util.cc
index 27bcf7b39d0ab54e79085fa7de46e3739e6842ea..330995cceb8d57c7807e013481e05767ed0828b7 100644
--- a/ppapi/shared_impl/file_system_util.cc
+++ b/ppapi/shared_impl/file_system_util.cc
@@ -4,6 +4,8 @@
 
 #include "ppapi/shared_impl/file_system_util.h"
 
+#include "base/logging.h"
+
 namespace ppapi {
 
 fileapi::FileSystemType PepperFileSystemTypeToFileSystemType(
@@ -32,4 +34,17 @@ bool FileSystemTypeHasQuota(PP_FileSystemType type) {
           type == PP_FILESYSTEMTYPE_LOCALPERSISTENT);
 }
 
+std::string IsolatedFileSystemTypeToRootName(
+    PP_IsolatedFileSystemType_Private type) {
+  switch (type) {
+    case PP_ISOLATEDFILESYSTEMTYPE_PRIVATE_CRX:
+      return "crxfs";
+    case PP_ISOLATEDFILESYSTEMTYPE_PRIVATE_PLUGINPRIVATE:
+      return "pluginprivate";
+    default:
+      NOTREACHED() << type;
+      return std::string();
+  }
+}
+
 }  // namespace ppapi